Enhanced Avalanche Capability and Ruggedness in 4H-SiC p-i-n Diode by Low-Angle Positive Beveled Edge Termination

In this work, a low-angle positive-bevel edge-termination (LAPBET) structure is realized in SiC using a p-type epitaxial layer. Experimental results show that the fabricated SiC p-i-n diodes achieve an almost ideal breakdown voltage, reaching approximately 99% of the theoretical parallel-plane limit. The obtained avalanche energy density ($\textit{E}_{\text{AS}}$) (11.5 J/cm2) and avalanche-induced current density ($\textit{J}_{\text{AVA}}$) (3.29 kA/cm2) are among the highest reported for SiC, GaN, and Ga2O3diodes. The enhanced avalanche capability is attributed to the uniformly distributed and smoothly confined electric field within the active region. Furthermore, no device degradation is observed after 1 000 000 avalanche cycles at 60$\textit{E}_{\text{AS}}$. These results demonstrate the strong potential of the LAPBET technique for robust avalanche-capable SiC power devices.